This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-07-24


2689. Are cv-qualified std::nullptr_t fundamental types?

Section: 6.8.2  [basic.fundamental]     Status: DRWP     Submitter: Anoop Rana     Date: 2022-12-08

[Accepted as a DR at the March, 2024 meeting.]

It is unclear whether cv std::nullptr_t is a fundamental type, given that it is declared in a library header and cv-qualifications are not mentioned in 6.8.2 [basic.fundamental] paragraph 15.

Proposed resolution (approved by CWG 2023-12-01):

Change in 6.8.2 [basic.fundamental] paragraph 15 as follows:

The types denoted by cv std::nullptr_t are distinct types. A value of type std::nullptr_t is a null pointer constant (7.3.12 [conv.ptr]). Such values participate in the pointer and the pointer-to-member conversions (7.3.12 [conv.ptr], 7.3.13 [conv.mem]). sizeof(std::nullptr_t) shall be equal to sizeof(void*).

The types described in this subclause are called fundamental types. [Note 11: Even if the implementation defines two or more fundamental types to have the same value representation, they are nevertheless different types. —end note]